Then, I am thinking: what is the value of the First Publication?

Probably to give the Apples, Samsungs, and Google's of the world a free look at what the little guys are doing so they can begin to reengineer/steal if they deem the patent worth while. The rules are written in favor of the companies that have/give the right people the most money. I believe they refer the initial 18 months as the period of time that the contents of the patent can remain "cloaked" after which the world can begin to pick it apart. JMO